We have a problem. My BM (see sig) will not take the replacement rear wheel I have prepared for it. Anyone here who can tell me about BM developments that mean this new wheel locks into the fins on the mating face of the bevel box? There are 12 protuberances around the bowl of this wheel, where the drive spline boss is riveted, which had been milled off my original wheel. I would like to know what changes lead to this difference in the wheels. Was the bevel box facing (?) plate strengthened at a later stage by these fins? What were these protuberances designed for (something to do with the drum brake perhaps)? What the fuck should I do for the best? (Nothing here for you Lozzo, walk away please) More specific BM sites are generally stumped by this question.